Automatic control valve for refrigerating systems



May 7, 192. J. L. SHRODE AUTOMATIC CONTROL VALVE FOR REFRIGERATING SYSTEMS 2 Sheets-Sheet Filed March 14, 1927 f 5m Z J. L.. ss waoamz LENS 3% AUTOMATIC CONTROL VALVE FOR REFRIGERATING SYSTEMS May 7 1?).29O

Filed March l4, i923? Patented May 7, A 1929.

UNITED STATES J'OEN L. SHRODE, 01?

ST. LOUIS MISSOURI.

AUTOMATIC OONTROL VALVE FOR REFRIGERATIN G SYSTEMS.

Application filed March ,14, 1927. Serial No. 175,248.

The object of this invention is to provide a simple, compact and efiicient device whereby a substantially constant'ratio between the temperature of the refrigerant and product to be refrigerated will be automatically maintained. The invention is illustrated in the accompanying drawings and will be hereinafter fully set forth.

In the drawings:

Figure 1 is a diagrammatic elevation of a refrigerating system in which the invention is embodied.

Figure '2 is an enlarged vertical section through the reducing valve and thermal control chamber.

Figure 3 is a section ontheline 3-3 of Figure 2.

Figure 4 is a section on the line 44 of Figure 3.

Referring to Figure 1, the reference numeral 1 denotes a compressor or pump which may be of any approved form, and 2 designates the condensing coils through which the refrigerant is caused tocirculate from the pump under pressure to be stored'in the receiver 3. A pi e 4 connects the receiver 3 with the inlet side of a pressure-regulating valve 5 and the cooling coil 6 is connected with the outlet side of the said valve. A casing 7 above the pressure-regulating valve is connected on one side with one end of the cooling coil 6 and on its other side is connected through a return pipe 8 with the compressor or pump 1.

The pressure-regulating valve, which is indicated as an entirety by the numeral 5 in Figure 1, comprises a block or casting 9 having an inlet port 10 in one sideconnected to the ipe 4, and at its opposite side having a discharge tube 11 which projects into the cooling coil 6. In the under side of the block or casting 9 is a central chamber 12 connected through a pasage 13 with the inner end of the inlet port 10, and this chamber 12 1s lish communication between the same and the discharge tube 11. At the upper end of the passage 18 is a packing box 20 whereby pack ing 21 will be held closely about the stem 22 and leakage of the refrigerant around the closed by. 1:. ca or plug 14 having a central -said stem will be avoided. This stem 22 has its lower end resting on the reduced upper end 23 of'the valve pin 24and acts as a medium through which pressure is applied to the valve 24 to open the valve and permit the refrigerant to flow through the passage 18 and out through the passage 19 into the cooling coils 6. It is evident that the spring 17 tends constantly to seat the valve and a greater pressure exerted through the stem 22 will force the valve 24 away from its seat, permittng the refrigerant to flow through the several passages into the cooling coil 6. The top or upper side of the block 7 or casting 9 is centrally recessed, as shown at 25, and an opening 26 is formed through the block to establish communication between the said recess 25 and the chamber or enlargement 27 surrounding the tube 11, and in communication with the cooling coil which has a flange connection bolted to the valve body or casting 9, as will be understood. A flexible diaphragm 28 extends across the recess or chamber 25 and the upper extremity of the stem 22 bears against the under side of said diaphragm, the diaphragm being secured by bolts 29 inserted throu h the flange 30 of an upper casting 31 and t rough the marginal. portion of the diaphragm into the top of the casting 9, as shown clearly in Figure 2. The casting 31 constitutes the body of the casing 7 and has a central bore or chamber 32 which is enlargedin its lower portion to define a cham ber 33 alined with the passage 18 in the valve block 9 and housing an expansion spring 34. The said spring 34 bears at its lower end upon a plate 35 which has'its under surface convex and resting directly upon the diaphragm, the point of contact being directly opposed to the upper end of the stem 22-. The upper end of the spring 34 bears against a plate 36", the upward movement of which is limited by contact with the shoulder 37 formed at the uprper end of the chamber 33 and the lower end of the bore 32. Threaded through the top of thecasting 31 is an adjusting rod 38 which has its upper end suitably formed to be engaged by a turning tool and its lower end resting upon the presser plate or cap plate 36, a packing box 39 being mounted on the top of the casting 31 around the adjusting rod to prevent leakage. By screwing down on the stem 38 the tension of the spring 34 may be regulated and pressure exerted to overcome ,the spring 17 and open the valve 24. Concen trio with the bore 32 a circular chamber or passage 4t) is formed in the casting 31 and a small port 41- is formed through the inner wall of this chamber to establish communication angles to the said valve 42 openings 43 are formed in the casting to receive the ends of the-coil 6 andthe pipe 8, as will be understood. Cap plates 4&- may be secured to the opposite sides of the cast-ing 31 around the ends of-the coil 6 and the pipe 8 respectively to hold packing to the'said element and thereby prevent leakage of the circulating refrigsure-regulating valve.

erant. To facilitate the application of these caps or packing plates,.threaded sockets 45 are provided in the sides of the casting 31, as shown most clearly in Figure 4.

The operation of the apparatus will, it is thought, be readily understood. The rcfrigerating medium in liquid form under high pressure passes from the receiver 3 through the pipe 4 to the inlet passage 10 of the pressure-regulating valve and thence flows through the passage 13 to the chamber 12 to rise through the passage 18 and pass out through the port- 19 into the cooling coil. The diaphragm 28 is subjected to the pressure of the gas in the-cooling coil through the opening 26 and is'also subjected to the pressure of the spring 17 exerted through the follower or plunger 16 and the valve 24. The adjusting rod 38 is rotated so that the tension of the spring 34 will just balance the pressure exerted on the underside of the diaphragm 28 and,'c onsequently, the valve 24 will be in open posit-ion so that circulation of the refrigerant may occur. The refrigerant flowing through the coil 6 will absorb heat from the surrounding air and, consequently, will be raised in temperature and will be capable of exerting a greaterpressure than when it entered the cooling coil. The heating of the refrigerant within the cooling coil and the retraction of heat from the surrounding air causes a deposit of frost upon the'coil and this frost ordinarily reaches back to'the pres- It is here to be noted that the diameter of the end 11 of'the cooling coil is not greater than the diameter of the inlet passage in the valve block 9 so that the refrigerantcannot expand within the valve and the expansion will not occur until the refrigerant has passed some distance from the valve so that there will be no deposit'of frost upon the valve to interfere wit-hits successful operation in my apparatus. 'lVhen a predetermined pressure isv obtained, in the coil 6 and circular chamber 40', the valve 42 is opened to establish the same-pressure in the thermal chamber 32. "The valve is then closed trapping a volume of gas inthe chamber 32 of the same pressure as that in the coil slightly.

frigerant is in direct relation to its pressure,

urally attained in the spring chamber 33 and is also transmitted to the top of the diaphragm 28. As the amount of pressure allowed in this chamber is somewhat less per square inch than the pressure of the spring 17, the valve will remain closed until an additional pressure is applied by screwing down on the adjusting stem 38. As the pressure of the gas in the-thermal chamber 32' and 33 is in direct relation to its temperature, it will be readily seen that any increase or decrease in temperature of the gas .in the chambers 32 and 33 will cause the valve to open or close respectively. The desired suction pressure at which the machine is to operate is provided by the adjusting stem 38 and a balanced condition between the springs 17 and 34: is set up, and any increase in pressure above or below the diaphragm 28 will cause the valve to open or close respectively. In other words, the opening and closing of the valve will be automatically governed by either an increase or decrease in pressure in the coil 6 and an increase or decrease in pressure of the gas in the chamber 32. It is readily seen' that as the machine operates, the coil 6 will become gradually cooled and as that part of the pipe that is connected to the block '31 becomes cooled, the cooling eflect on the gas trapped in the chamber 32, will cause a decrease in pressure which will cause the valve 24 to close As the temperature of the rethe slight closing of the valve will permit less refrigerant to flow, but at a lower temperature, through the coil 6. This lowering of temperature of the refrigerant will further cool the inert gas in the chambers 32 and 33 thereby further decreasing the pressure, which in turn will cause the valve to close still more. This closing of the valve is continually going on until the room that is being refrigerated is brought to the desired temperature, at which point the machine will becaused to stop-by the action of a thermostat -in the room. When the machine stops, re-

frigerant will continue to flow into, the coil 6 increasing the pressure therein. This pressure will be transmitted through the passage 27 and through the orifice 26 into the recess 25 and exert its pressure on the diaphragm 28 causing the valve to close and re- J main closed until the machine again starts.

Havlng thus described the invention, I claim:

a 1. In a refrigeratin system, the combinat1on of a pressure regu ator including a valve block having an inlet and an outlet, a diaphragm over the block, a passage lateral to the outlet leading from the cooling coil of the system to the diaphragm for subjecting one side of said diaphragm to the pressure in the cooling coil, the outlet from the valve block extending into the coil at a point remunication with the return line of'the refrigerating system, a pressure plate within the thermal chamber receiving pressure through the by-pass and bearing on the diaphragm in opposition to the valve, and means for regulating the normal pressure of said plate.

n a refrigerating system, the combination of a valve block having a central recess in'its upper side and having inlet and outlet passages and an enlarged bore around the outlet passage and an opening extending between said bore and said recess, a discharge tube leading from the inner part of the outlet passage through the enlarged bore of said passage into the cooling coil, a diaphragm secured upon the block and extendingover said recess, a valve yieldably mounted in the valve block between the inlet and outlet passages and exerting pressure against the diaphragm, a block secured upon the valve blockover the recess in the top thereof, a thermal chamber within the last-mentioned block, a return line passage through the block, a pressure plate mounted in the thermal chamber and bearing yieldably upon the diaphragm in opposition to the valve, and a port above the ressure plate establishing communication etween the return line passage and the thermal chamber.

3. A valve structure for the purpose set forth comprising a body having inlet and outlet passages, a diaphragm over said body, a valve between the inlet and outlet passages, means tending to raise the diaphragm for seating the Valve, a body secured on the valve body over the diaphragm and having a thermal chamber open to the diaphragm and having an annular chamber around the thermal chamber, said thermal chamber having a stop shoulder intermediate its height, a pressure plate within the chamber below said shoulder, an expansion spring between said plate and the diaphragm, an adjusting screw mounted in the top of the last-mentioned body and bearing on the pressure plate whereby'pressure may be exerted on the diaphrgm 1n opposition to the means tending to raise the same,

a port in the wall of the thermal chamber,

and a valve mounted in the Wall of the circular chamber to close said ort.

In testimony whereof aflix my si ature. JOHN L. SHRODE. 8.] 

